Questions about Mathematica's date and time functions.

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0
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25 views

Time and distance problem [on hold]

A train starts from Jammu for Srinagar at 13:30 and reaches Srinagar at 17:30. Another train starts from Srinagar at 15:30 and reaches Jammu at 19:00. At what time will the trains meet?. I have ...
0
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0answers
12 views

Trilateration Using TDOA [migrated]

I am having some trouble to find or implement an algorithm to find a signal source. The objective of my work is to find the sound emitter position. To accomplish this I am using three vibration ...
4
votes
4answers
387 views

How to convert Dates with format 2016/03/1 to become {2016,3,1}

I have a problem to convert tide data with the form as follows. 2016/03/23,08:00,0.89,* 2016/03/23,09:00,1.41,* 2016/03/23,10:00,1.67,* 2016/03/23,11:00,1.44,* 2016/03/23,12:00,0.82,* ...
3
votes
1answer
59 views

overlap of data

I have two individual Date lists as Date Objects: List 1 = {1 Jan 1991 9 :00 , 3 Jan 1991 11:00 ..etc } List 2 ={ 7 Jan 1991 14:00, 9 Jan 1991 15:00 ..etc} For ...
4
votes
2answers
79 views

How to override DisplayForm of (mixed) time Quantity

What's the best approach to overriding DisplayForm for specific types of Quantity eg time especially w/ mixed units? Current is ...
3
votes
1answer
82 views

How to plot the hour of the sunsets

i have this code: ...
-1
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2answers
61 views

Matching timestamped data

I bet this question is a gimme for most of you guys, but I'm having a bit o' trouble figuring it out. Thanks ahead of time for your input and help. Soooo, I have two datasets where column 1 is a ...
8
votes
2answers
224 views

How to skip weekends in DateListPlot?

How to skip weekends in DateListPlot, ie, drawing 20 something data points for a month and not leaving 2 days gap between weeks? Currently DateListPlot occupied the actual number of days for a month ...
0
votes
1answer
46 views

Combining first 5 columns from CSV file into AbsoluteTime date

Thanks in advance for all your help. I need to import data from a CSV file that looks like : (easier to read in excel) I would like to convert the data into timestamps by creating a Table with 2 ...
3
votes
1answer
43 views

How to get DateListPlot Epilog to display shapes

The following should produced a plot with an orange outlined disc labelled "A" on the dotted line. Epilog produces the dotted line and the text label but is unable ...
2
votes
1answer
100 views

Automatic text-wrapping in labels in `TimelinePlot`

Part-related to this question and part-related to this one, I would like to make use of the new features of TimelinePlot in 10.3, but would like to incorporate some ...
3
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0answers
49 views

Possible Bug with DateObject

So my questions is going to be hard to duplicate because I am not sure when or why it happens. I've read here several bugs with DateObject, but none of them ...
3
votes
1answer
39 views

How to modify wrong time zone in a Date object?

How can one modify the wrong time zone in a DateObject, without a conversion? Can one manipulate the TimeZone directly without having the numerical value of the time changing?
0
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0answers
42 views
2
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1answer
95 views

working hours and negative time [closed]

I have a list of TimeObjects. I want to subtract 5h from each element and if TimeObject < 5h then give a negative hour. My ...
4
votes
1answer
50 views

TimelinePlot - Handling dates prior to Year Zero

Interested in Using TimelinePlot to help me understand/remember important time periods in Earth prehistory and history. Following an a simple example in the Documentation I create a TimelinePlot for ...
5
votes
2answers
96 views

How can DateObject handle calender weeks

I have dates given for a TimeLinePlot. These dates are in {year,week} format. DateObject ...
6
votes
2answers
135 views

Plot time along the y-axis?

How can I plot times along the Y-axis, (with dates along the X-axis) e.g. ...
2
votes
2answers
43 views

Date Conversion Using Regular Expressions on “Incomplete” Date Formats

I have a list of dates in one of the following formats: "1999/05/12", "1999/05/", "1999//", "****//**/", "" so that a list of such dates might appear as ...
1
vote
1answer
91 views

Why do I get different results for the same input specified using natural language phrasing? [closed]

One of the comments to Stephen Wolfram's blog post on Ada Lovelace, mentioned that WolframAlpha (and verified in Mathematica as well) provided slightly different results for the question of Ada's age ...
1
vote
0answers
34 views

Save a Mathematica notebook evaluated [duplicate]

My notebooks can take some time to evaluate and by quitting Mathematica, I have to reevaluate every definition I've made once I restart Mathematica. Is there a way to tell Mathematica to save the ...
4
votes
2answers
141 views

Finding the positions DateList dates in a range in large data set

There are similar questions to this like list search but this question is focused on finding at subset of dates in DateList format within a range of specified dates ...
5
votes
2answers
141 views

How to convert date string with fractional seconds to DateObject

I have a date/time string from a data file in the form "2014/01/09 07:24:36:001". I would like to convert it to a DateObject. I ...
10
votes
1answer
182 views

DateDifference isn't consistent when giving result in years

This isn't really causing me a problem at the moment, but it's weird. Is this documented anywhere? When I ask for the difference in days and then in years between April 1, 2015 and October 1, 2015 ...
4
votes
1answer
69 views

Working with dates & times - nonatomic expression expected [closed]

Please note that I am new to Mathematica. I am endeavouring to import data from a CSV file with the first column a date and time. The import appears to work fine and returns the results I expect: ...
5
votes
3answers
87 views

How to ignore year in DateListPlot

I just upgraded to Mathematica 10, and I am trying to get the hang of the new TimeSeries data objects, which are preventing my old strategy of overlaying data from ...
4
votes
0answers
36 views

DateObject's DateFormat option has inconsistent result in TimelinePlot LabelingFunction and by direct call

I want to strip time and time zone from dates in the LabelingFunction of a TimelinePlot. I am using the ...
7
votes
1answer
614 views

Why does Mathematica's date for the battle Agincourt differ from the US Navy's?

If I ask Mathematica for the Julian Date for the battle of Agincourt with WolframAlpha["battle of agincourt date"] it reports ...
2
votes
1answer
104 views

DateListPlot show iso week

How can I make DateListPlot show the iso week number? I would like to make a Date plot so that for each dot it will show the iso week date in the x-axis .
13
votes
4answers
366 views

How to evaluate the second argument of Cases only once

I'd like to find a fast but readable way to achieve the following: ...
1
vote
1answer
40 views

Aborting an evaluation automatically after a specified time elapsed

I use the following code to evaluate a series of notebooks: nb1 = NotebookOpen["C:\\Users\\....nb"]; SelectionMove[nb1, All, Notebook] SelectionEvaluate[nb1] ...
3
votes
2answers
97 views

Troubles importing date and time from CSV file

I'm trying to import CSV file with the following format: 20150803 00:00:01.649,1.09675,1.09678 using this code: ...
3
votes
2answers
151 views

Convert DateObject into TimeObject

How to elegantly convert from DateObject to TimeObject? The purpose is to extract time from the DateObject and manipulate only ...
7
votes
1answer
158 views

Determining FinancialData for Countries

How do I determine the FinancialData for Australia. For instance the one for USA follows as: FinancialData["NYSE", "Members"] ...
5
votes
1answer
108 views

DatePlus changes in V10.2, can I return to previous behaviour?

Now in V10.2, DatePlus has changed it behaviour in a undocumented way. Now, DatePlus[n] (with n as ...
2
votes
1answer
97 views

DateListPlot incorrect time zone [closed]

I'm trying to plot energy usage over time using datelistplot but the time zone on the ticks is wrong, data for 7pm shows as 3am The code: ...
4
votes
0answers
89 views

TimelinePlot with Interval in Associations

Bug introduced in 10.2 This is related to a previous question I asked about TimelinePlot and multiple associations (Behavior of TimelinePlot with multiple ...
0
votes
0answers
75 views

How to extract the time t of an interpolated function created by NDSolve? [duplicate]

I'm working with the function NDSolve. I give it the time of integration, the time I want it to evaluate my differential equations. Sometimes, it crashes before the end of its attribuated time ; For ...
2
votes
1answer
41 views

How to adjust the FrameTicks length in DateListPlot?

suppose I have the data for DateListPlot: ...
6
votes
4answers
296 views

How to combine Date and Time objects into DateTime object?

Considering a DateObject d and TimeObject t: ...
1
vote
1answer
175 views

How to make a cumulative time plot?

So I'm working with this data set where there is just one input(a date and time) per line in a .csv file. I've let Mathematica understand the input using "DateStringFormat". The time looks like ...
7
votes
2answers
374 views

How much time should one give Mathematica for an integral evaluation?

Sometimes when I do integrals in Mathematica (M), it keeps thinking and thinking and I have no idea what is going on inside M. For how long should one wait or how does one know whether M has not got ...
7
votes
3answers
226 views

Problem About TimelinePlot

Bug introduced in 10.1 and fixed in 10.3 TimeLinePlot was introduced in 10.1 I have some data from wikipedia. ...
2
votes
3answers
396 views

Converting timestamps into a decimal in minutes

I am importing a list of timestamps (hour:minutes:seconds) from a series of text files. I have the list: ...
5
votes
1answer
110 views

Handy dates conversion

I feel like something very basic is missing me, $dateformat = {"Year", "Month", "Day", "Hour"}; date = DateString[$dateformat] DateString["Date"] ...
0
votes
0answers
42 views

Speeding up a “filling in” process

I have a sparse EventSeries that looks something like ...
0
votes
1answer
91 views

My simulation is not never finishing and it is taking so much time?

I am running simple code which involves calculation of two first order differential equations.It is taking so much time and i am unable to get the results as the simulation is never finishing. ...
4
votes
3answers
346 views

How could I transform the YYYYDDD date string/Integer to YYYYMMDD date string?

suppose I have lots of YYYYDDD date Integers which look like(for example): ...
5
votes
4answers
213 views

DateListPlot: Highs and Lows

I have this data: ...
5
votes
1answer
189 views

Problems with TimelinePlot

I'm trying to play with the example in this recent blog post, but I'm having a few basic issues with TimelinePlot: Labels are getting cut off: How can I get ...